Not sure if it's due to the coding or the graphics, but sometimes, if you click the "Skip turn" button in a battle, weird things will happen:
http://prntscr.com/3xkyug
Sometimes if a Pokemon receives damage then heals up in the same turn, the HP bar will display the wrong percentage of HP left. In this case, the HP bar of Simisage only shows its HP left after Glalie's Ice Shard, not including the HP gained from Giga Drain.
http://prntscr.com/3xkw5w
Throh has broken Mega Mawile's Substitute, but it is still "hidden" behind.
http://prntscr.com/3xkyug
Sometimes if a Pokemon receives damage then heals up in the same turn, the HP bar will display the wrong percentage of HP left. In this case, the HP bar of Simisage only shows its HP left after Glalie's Ice Shard, not including the HP gained from Giga Drain.
http://prntscr.com/3xkw5w
Throh has broken Mega Mawile's Substitute, but it is still "hidden" behind.